The present invention relates to a new and distinct variety of Prunus persica L. Batsch white flat peach tree. This new tree, named ‘FLATQUEEN’, produces very long lifetime, good eating quality, semi-freestone flesh fruit for fresh market in August in the 66—Pyrénées Orientales departement—France. Contrast is made to ‘MAILLARFLAT’ (unpatented) flat peach, ‘O Henry Mercil’ yellow peach (U.S. Plant Pat. No. 4,399), standard varieties, for reliable description. ‘FLATQUEEN’ is a promising candidate for commercial success in that it has a late evenness of maturity, a very aromatic taste and fruit is the same as ‘MAILLARFLAT’ (unpatented), ‘FLATPRETTY’ (U.S. Plant Pat. application Publication No. 20060265795), ‘FLATNICE’ (unpatented) and ‘FLATPRINCESSE’ (U.S. Plant Pat. application publication No. 20060265796).